5 Forgotten Chevrolet and GMC Truck Concepts That Were Never Built (And What We Got Instead)

• November 4, 2020
• Story By
  Benjamin Hunting

General Motors has long had a history of throwing down impressive concept trucks that simply disappear after their tour of the auto shows is over. Some of these pickups and SUVs would see their technology and features trickle down into production models, but the vast majority were instead swallowed up the by silence of time, never again to show their carefully polished faces to the world. 

Which forgotten Chevrolet and GMC truck concepts were the most intriguing? What did the General choose to build instead of these one-off flirtations with the future? Here's our look at five of the coolest GM concepts that never made it into production.

1. 1988 GMC Centaur

What Was It?

The late '80s were a transitional time for automakers embracing a host of new technologies that would end the Malaise Era and introduce more advanced vehicle designs. This made concepts of the period fairly wild in terms of their visual presentation, and the GMC Centaur was no exception.

Intended to split the difference between cars and trucks, the Centaur took on a stretched 'ute look that was ultra-futuristic business in the front and long-bed party in the back.

Why Was It Never Built?

The AMC Eagle—the first true 'crossover'—hadn't exactly been a runaway sales success, and the Chevrolet El Camino had been retired the year before, so there was no clear path to market for an oddball like the Centaur.

Then there was its four-wheel steering system paired with the rear-engine V6 sitting underneath the cargo bed. The latter was an engineering flight of fancy that would have made for weird driving dynamics when empty and a terrifying push when fully loaded.

What Did We Get Instead?

One look at the Centaur and it's clear to see the roots of the Chevrolet Lumina / Pontiac Trans Sport / Oldsmobile Silhouette minivans that would debut just a couple of years later.

In fact, the Centaur was closer to the final product than the actual Pontiac Trans Sport concept that had appeared earlier in the decade. On the truck side of things, we'd have to wait until 2002 before GM would introduce 'Quadrasteer' on its full-size trucks.

2. 2003 Chevrolet Cheyenne

What Was It?

The Chevrolet Cheyenne name dates all the way back to the 1970s when it was first used to denote particularly upscale versions of the C/K pickup. In 2003, the name was revived for an unusual concept that featured a number of features not typically found on the truck scene.

Of these, the most prominent were its aluminum chassis, its use of an independent rear suspension instead of a solid axle, and a short hood that reduced the truck's front overhang. A system of integrated storage lockers and side access doors for the cargo bed were also included, along with a dramatically low load floor made possible by the compact IRS setup.

Why Was It Never Built?

Although the Cheyenne's four-wheel steering system was already in use by a number of GM trucks (as mentioned above), it was difficult to understand why Chevrolet would move away from the steel frame, solid axle pickup platform it had been relying on for decades, which was rugged and inexpensive to build.

Gas was still cheap enough to keep concerns like vehicle weight on the back burner, and the brand already had a cargo management system available through the Avalanche crossover pickup.

What Did We Get Instead?

The schnozzle on the Cheyenne was similar to the generic front fascia Chevrolet that would work its way across the brand's entire line-up, with its closest cousin found on the Uplander people mover.

From a truck standpoint, however, it was the multi-displacement system's cylinder deactivation technology offered by the concept's 500hp supercharged V8 that would eventually trickle down to production pickups by the end of the decade.

3. 2000 GMC Terradyne

What Was It?

Right around the dawn of the new millennium, heavy duty pickups began to morph into the gargantuan behemoths that they are today.

Although GM was a little behind Ford in terms of puffing up the chest of its 2500-and-up trucks, the GMC Terradyne concept showed us all what was just over the horizon, with its brutal angles, bulky bed and hood, and massive ground clearance all quite prescient.

Why Was It Never Built?

Rear-hinged doors were in vogue on certain full-size trucks of the time, but the Terradyne's sliders and lack of B-pillar would never have passed crash testing, nor would they have withstood the same levels of abuse as a traditional door over the same period of time.

More important, however, the Terradyne was never built because it was intended to show off trends in GM's styling and engineering department rather than presage an actual production vehicle.

What Did We Get Instead?

The ideas shown off by the GMC Terradyne continue to make an impact today, as the brand's commercial trucks are clearly descended from the same ethos that guided the massive, unforgiving sheet metal of the concept.

The turbocharged V8 turbodiesel engine tucked into the truck's cavernous engine bay was also right on point, what with its 700-plus lb-ft of torque, and the Compaq laptop stowed in the center console was a nod to the mobile office market that truck builders were only beginning to recognize at the time.

4. 2006 Chevrolet Silverado 427 Concept

What Was It?

In 2006, Chevrolet took its last swing at building a street truck with the Silverado 427 concept. Featuring a 7.0L LS7 V8 rated at 505hp, and backed by a six-speed manual transmission.

The 427 rode on a lowered suspension, shunned four-wheel drive, and featured a prominent hood scoop. Massive 22-inch rims, unheard of on a factory vehicle, helped transmit all of that grunt to the ground.

Why Was It Never Built?

At the time, Chevrolet was on the outside looking in at an ultra-high performance pickup truck market that had birthed both the Ford SVT Lightning and the Dodge Ram SRT-10. Although it marketed the Silverado SS, with a 6.0L V8, it was nowhere near as quick as the supercharged Ford or the Viper-powered Ram.

These tire-shredding monstrosities, however, burned bright and then disappeared almost as quickly; Ford had already decided not to pursue a third-generation Lightning, while the Ram SRT-10 would be gone at the end of that year. Without any competition, GM had to decide whether it wanted to soak up any remaining interest in muscle trucks, or interpret the decision of its rivals to vacate the segment as a sign that the profits simply weren't there. It chose door number two.

What Did We Get Instead?

Chevrolet never again ventured into street truck territory, but it would continue to tease buyers with concepts like the revitalized Cheyenne in 2014.

The Cheyenne offered a 6.2L mill good for 420hp combined with a lightened pickup platform enhanced by carbon fiber and a number of Camaro-sourced suspension components.

5. 2008 GMC Denali XT Concept

What Was It?

The GMC Denali XT Concept was a wild unibody take on the luxury crossover.

Combining the ride quality of a sedan and the utility of a 'ute-like cargo bed, the Denali XT was aimed squarely at the wave of funky import pickups that never materialized. Think of it as GM's rear-wheel drive answer to the Ridgeline.

Why Was It Never Built?

The GMC Denali XT had the misfortune of being inspired by three trends on the verge of disappearing from the automotive industry in 2008. The first was the 'ute, a car-truck combo that had definitely died in North America 20 years beforehand but which was still alive and well in Australia, and which a small but vocal group of enthusiasts had been clamoring for.

This brings us to the second of the Denali XT's trouble points, which was the perceived synergies between GM and its Holden subsidiary Down Under that would never quite materialize (with only the slow-selling Pontiac GTO and G8 to show as a result).

Finally, there was the unibody pickup craze that simply never happened, as Chinese companies remained locked out of the U.S. over safety concerns and Toyota and Hyundai bided their time by keeping the A-BAT and the Veracruz in concept form only.

What Did We Get Instead?

Sport-utility trucks, or SUTs, were on their last legs when the Denali XT appeared, with the Explorer Sport Trac and the Hummer H3T representing the last of the breed.

GM's impending bankruptcy would wipe out the most promising part of the XT, its two-mode hybrid drivetrain, which might have given pickup truck buyers a second generation of the successful system that had previously been offered in the Chevrolet Silverado and GMC Sierra (as well as several other full-size SUVs from GM).